Start heating a skillet on the stove.
Place the chicken thigh fillets between sheets of cling film and pound to a uniform thickness. One-fourth inch thickness is ideal for quick cooking. Sprinkle with salt, pepper, cayenne, garlic powder and onion powder.
Place the seasoned chicken on the pre-heated skillet and cook over high heat for two minutes per side.
While the chicken cooks, prepare the garnishes. In this case, the "garnishes" were prepared in the form of a simple salad. Shred the lettuce. Halve the cherry tomatoes. Peel, de-seed and cut the cucumber into small cubes. Toss them all together with the scallions in a bowl. Drizzle in enough vinaigrette to moisten them and toss once more.
Take the chicken off the skillet and transfer to a chopping board.
Warm the tortilla on both sides in the still hot skillet.
Slice or chop the chicken.
Place the warmed tortilla on a plate. Spoon the salad on the tortilla, top with the grilled chicken and sprinkle in some torn cilantro.
Enjoy your chicken fajita!